Initial scaffold: Turborepo monorepo + design wiki

Turborepo (pnpm workspaces) with all dependencies pinned to latest
mutually-compatible versions: turbo 2.9, TypeScript 6, Fastify 5,
React 19, Vite 8, better-sqlite3 12 + Drizzle ORM 0.45.

Layout:
- apps/server   Fastify backend (local JWT auth + role guard, /health)
- apps/web      React 19 + Vite 8 operator SPA
- packages/db   Drizzle schema on SQLite/WAL; append-only events + users
- packages/devices  reader/printer/relay adapter interfaces (intent-only relay)
- packages/shared   shared domain types

Architecture constraints from the design wiki are encoded in the scaffold:
append-only hash-chained + signed event log, device-agnostic adapters,
"a barrier is not a door" (relay expresses intent only), fully-local
offline-first auth.

wiki/ is an LLM-maintained Obsidian knowledge base (28 pages) ingested
from the architecture & design notes, with its own maintenance schema.

Verified: pnpm install, full turbo build (5/5), server boots and serves
/health, drizzle-kit generates the initial migration.

wiki/concepts/network-isolation.md

@@ -0,0 +1,22 @@
+---
+type: concept
+tags: [parking, security, network, access-control]
+sources: [parking-system-architecture]
+updated: 2026-06-14
+---
+
+# Network Isolation
+
+**Mandatory** mitigation for the unauthenticated [[uhppote-udp-protocol]]: because the
+[[uhppote-controller]] can't authenticate, the **network must be the security boundary** (the
+[[trust-boundary]] = the network). (See [[parking-system-architecture]] §6.)
+
+- Control devices go on **their own VLAN** with **no route** to the booth/office network and
+  **no wireless bridge**.
+- Requires a **managed VLAN switch** (in the [[bom]]).
+- Only when *only the host* can reach the controller does the controller's event log become a
+  trustworthy audit source (combined with [[event-log-ingestion]] + the
+  [[append-only-event-chain]]).
+
+This makes the UHPPOTE setup **tamper-evident behind isolation** — but never tamper-*proof*;
+that requires the [[esp32-custom-controller]].